In order to increase engine output power and acceleration response of spark ignition engines in automobiles, oxygen-containing additives such as alcohols (e.g., methanol, ethanol), ethers (e.g., methyl-t-butyl ether) and ketones (e.g., acetone) have been studied. Further, as additives of fuel for automobile racing, hydrozine and nitro compounds (e.g., nitroparaffins such as nitromethane and nitropropane, nitrobenzene) have been investigated. Those additives, however, often give adverse effects to the engine and its components.
It is also known that organometallic compounds (e.g., ferrocene, methylcyclopentadienyl manganese tricarbonyl, alkyl lead such as tetraethyl lead) and aromatic amines (e.g., aniline, monomethyl aniline and dimethyl aniline) can be used as anti-knocking agents. However, it has been confirmed that those compounds poison three-way catalysts of catalytic converters for treating the exhaust gas and consequently that they reduce the catalysis efficiency. Japanese Patent Provisional Publication No. 58-104996 (corresponding to U.S. Pat. No. 4,409,000) describes that carburetors and engines can be cleaned by adding alkyl amine or ethylene oxide-adducted alkenyl amine into automobile fuel.
European Patent No. 869163 A1 describes that the addition of N,N-bis(hydroxyalkyl)alkylamine to gasoline reduces friction of gasoline engines.
According to PCT Patent Publication No. 2001-502374 (WO-98/17746), solubility in water as well as engine performance can be improved by adding fatty acid diethanol amide, alcohol ethoxylate or fatty acid ethoxylate into liquid fuel such as gasoline or diesel fuel.
It is an object of the present invention to provide a fuel additive composition which is added into a fuel such as gasoline to improve driving performance, in particular, acceleration performance of automobiles without giving any adverse effect to the internal combustion engines.
It is another object of the present invention to provide an automobile fuel, such as gasoline, containing the above fuel additive composition.